A growing number of buildings in North America have foundations or exterior walls of concrete sheathed with foam or another permeable material on the outside. To prevent the free passage of subterranean termites vertically up through the sheathing and into wood members of the building they often include a termnite shield. In this application a termite shield is a strip of sheet metal placed through the foam along a continuous horizontal line around the entire perimeter of the building, either shortly above or shortly below grade. Termites tunneling up within the foam hit the shield, whereupon they must either quit their upward journey or exit the foam to go around the shield. Once outside the foam they can be detected and/or treated with pesticides.